LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 5 of total 5

Search options

  1. Article ; Online: 27-hydroxycholesterol decreases cell proliferation in colon cancer cell lines.

    Warns, Jessica / Marwarha, Gurdeep / Freking, Natalie / Ghribi, Othman

    Biochimie

    2018  Volume 153, Page(s) 171–180

    Abstract: Colorectal cancer (CRC) is the third most diagnosed cancer in the western world, affecting 1 out of approximately 22 people in their lifetime. Several epidemiological studies suggest a positive association between high plasma cholesterol levels and ... ...

    Abstract Colorectal cancer (CRC) is the third most diagnosed cancer in the western world, affecting 1 out of approximately 22 people in their lifetime. Several epidemiological studies suggest a positive association between high plasma cholesterol levels and colorectal cancer. However, the molecular mechanisms by which cholesterol may alter the risk of colorectal cancer (CRC) are ill-defined as the cholesterol lowering drugs statins do not appear to decrease a patient's risk of developing colorectal cancer. Cholesterol is metabolized to active derivatives including cholesterol oxidization products (COP), known as oxysterols, which have been shown to alter cellular proliferation. These metabolites and not cholesterol per se, may therefore affect the risk of developing colorectal cancer. The cholesterol metabolite or the oxysterol 27-hydroxycholesterol (27-OHC) is the most abundant oxysterol in the plasma and has been shown to be involved in the pathogenesis of several cancers including breast and prostate cancer. However, the role of 27-OHC in colorectal cancer has not been investigated. We treated Caco2 and SW620, two well characterized colon cancer cells with low, physiological and high concentrations of 27-OHC, and found that 27-OHC reduces cellular proliferation in these cells. We also found that the effects of 27-OHC on cell proliferation are not due to cellular cytotoxicity or apoptotic cellular death. Additionally, 27-OHC-induced reduction in cell proliferation is independent of actions on its target nuclear receptors, liver-X-receptors (LXR) and estrogen receptors (ER) activation. Instead, our study demonstrates that 27-OHC significantly decreases AKT activation, a major protein kinase involved in the pathogenesis of cancer as it regulates cell cycle progression, protein synthesis, and cellular survival. Our data shows that treatment with 27-OHC substantially decreases the activation of AKT by reducing levels of its active form, p-AKT, in Caco2 cells but not SW620 cells. All-together, our results show for the first time that the cholesterol metabolite 27-OHC reduces cell proliferation in colorectal cancer cells.
    MeSH term(s) Antineoplastic Agents/pharmacology ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Colonic Neoplasms/pathology ; Humans ; Hydroxycholesterols/pharmacology ; Liver X Receptors/metabolism ; Proto-Oncogene Proteins c-akt/metabolism ; Receptors, Estrogen/metabolism
    Chemical Substances Antineoplastic Agents ; Hydroxycholesterols ; Liver X Receptors ; Receptors, Estrogen ; 27-hydroxycholesterol (6T2NA6P5SQ) ; Proto-Oncogene Proteins c-akt (EC 2.7.11.1)
    Language English
    Publishing date 2018-07-24
    Publishing country France
    Document type Journal Article
    ZDB-ID 120345-9
    ISSN 1638-6183 ; 0300-9084
    ISSN (online) 1638-6183
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2018.07.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: 27-hydroxycholesterol decreases cell proliferation in colon cancer cell lines

    Warns, Jessica / Marwarha, Gurdeep / Freking, Natalie / Ghribi, Othman

    Biochimie. 2018 Oct., v. 153

    2018  

    Abstract: Colorectal cancer (CRC) is the third most diagnosed cancer in the western world, affecting 1 out of approximately 22 people in their lifetime. Several epidemiological studies suggest a positive association between high plasma cholesterol levels and ... ...

    Abstract Colorectal cancer (CRC) is the third most diagnosed cancer in the western world, affecting 1 out of approximately 22 people in their lifetime. Several epidemiological studies suggest a positive association between high plasma cholesterol levels and colorectal cancer. However, the molecular mechanisms by which cholesterol may alter the risk of colorectal cancer (CRC) are ill-defined as the cholesterol lowering drugs statins do not appear to decrease a patient's risk of developing colorectal cancer. Cholesterol is metabolized to active derivatives including cholesterol oxidization products (COP), known as oxysterols, which have been shown to alter cellular proliferation. These metabolites and not cholesterol per se, may therefore affect the risk of developing colorectal cancer. The cholesterol metabolite or the oxysterol 27-hydroxycholesterol (27-OHC) is the most abundant oxysterol in the plasma and has been shown to be involved in the pathogenesis of several cancers including breast and prostate cancer. However, the role of 27-OHC in colorectal cancer has not been investigated. We treated Caco2 and SW620, two well characterized colon cancer cells with low, physiological and high concentrations of 27-OHC, and found that 27-OHC reduces cellular proliferation in these cells. We also found that the effects of 27-OHC on cell proliferation are not due to cellular cytotoxicity or apoptotic cellular death. Additionally, 27-OHC-induced reduction in cell proliferation is independent of actions on its target nuclear receptors, liver-X-receptors (LXR) and estrogen receptors (ER) activation. Instead, our study demonstrates that 27-OHC significantly decreases AKT activation, a major protein kinase involved in the pathogenesis of cancer as it regulates cell cycle progression, protein synthesis, and cellular survival. Our data shows that treatment with 27-OHC substantially decreases the activation of AKT by reducing levels of its active form, p-AKT, in Caco2 cells but not SW620 cells. All-together, our results show for the first time that the cholesterol metabolite 27-OHC reduces cell proliferation in colorectal cancer cells.
    Keywords anticholesteremic agents ; apoptosis ; breasts ; cell cycle ; cell proliferation ; colorectal neoplasms ; cytotoxicity ; epidemiological studies ; estrogen receptors ; human cell lines ; metabolites ; neoplasm cells ; oxysterols ; pathogenesis ; patients ; people ; prostatic neoplasms ; protein kinases ; protein synthesis ; risk
    Language English
    Dates of publication 2018-10
    Size p. 171-180.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 120345-9
    ISSN 0300-9084
    ISSN 0300-9084
    DOI 10.1016/j.biochi.2018.07.006
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  3. Article ; Online: Connecting the dots: chromatin and alternative splicing in EMT.

    Warns, Jessica A / Davie, James R / Dhasarathy, Archana

    Biochemistry and cell biology = Biochimie et biologie cellulaire

    2016  Volume 94, Issue 1, Page(s) 12–25

    Abstract: Nature has devised sophisticated cellular machinery to process mRNA transcripts produced by RNA Polymerase II, removing intronic regions and connecting exons together, to produce mature RNAs. This process, known as splicing, is very closely linked to ... ...

    Abstract Nature has devised sophisticated cellular machinery to process mRNA transcripts produced by RNA Polymerase II, removing intronic regions and connecting exons together, to produce mature RNAs. This process, known as splicing, is very closely linked to transcription. Alternative splicing, or the ability to produce different combinations of exons that are spliced together from the same genomic template, is a fundamental means of regulating protein complexity. Similar to transcription, both constitutive and alternative splicing can be regulated by chromatin and its associated factors in response to various signal transduction pathways activated by external stimuli. This regulation can vary between different cell types, and interference with these pathways can lead to changes in splicing, often resulting in aberrant cellular states and disease. The epithelial to mesenchymal transition (EMT), which leads to cancer metastasis, is influenced by alternative splicing events of chromatin remodelers and epigenetic factors such as DNA methylation and non-coding RNAs. In this review, we will discuss the role of epigenetic factors including chromatin, chromatin remodelers, DNA methyltransferases, and microRNAs in the context of alternative splicing, and discuss their potential involvement in alternative splicing during the EMT process.
    MeSH term(s) Alternative Splicing ; Chromatin/metabolism ; Chromatin Assembly and Disassembly ; DNA Methylation ; Epithelial-Mesenchymal Transition/genetics ; Exons ; Histone Code ; Humans ; Introns ; Neoplasms/chemistry ; Neoplasms/genetics ; Nucleosomes/metabolism ; RNA Polymerase II/metabolism ; RNA Precursors/chemistry ; RNA Precursors/genetics ; RNA, Messenger/genetics ; RNA, Untranslated/chemistry ; RNA, Untranslated/genetics ; Signal Transduction ; Transcription, Genetic
    Chemical Substances Chromatin ; Nucleosomes ; RNA Precursors ; RNA, Messenger ; RNA, Untranslated ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2016-02
    Publishing country Canada
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 54104-7
    ISSN 1208-6002 ; 0829-8211
    ISSN (online) 1208-6002
    ISSN 0829-8211
    DOI 10.1139/bcb-2015-0053
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article ; Online: RNA polymerase II pausing can be retained or acquired during activation of genes involved in the epithelial to mesenchymal transition.

    Samarakkody, Ann / Abbas, Ata / Scheidegger, Adam / Warns, Jessica / Nnoli, Oscar / Jokinen, Bradley / Zarns, Kris / Kubat, Brooke / Dhasarathy, Archana / Nechaev, Sergei

    Nucleic acids research

    2015  Volume 43, Issue 8, Page(s) 3938–3949

    Abstract: Promoter-proximal RNA polymerase II (Pol II) pausing is implicated in the regulation of gene transcription. However, the mechanisms of pausing including its dynamics during transcriptional responses remain to be fully understood. We performed global ... ...

    Abstract Promoter-proximal RNA polymerase II (Pol II) pausing is implicated in the regulation of gene transcription. However, the mechanisms of pausing including its dynamics during transcriptional responses remain to be fully understood. We performed global analysis of short capped RNAs and Pol II Chromatin Immunoprecipitation sequencing in MCF-7 breast cancer cells to map Pol II pausing across the genome, and used permanganate footprinting to specifically follow pausing during transcriptional activation of several genes involved in the epithelial to mesenchymal transition (EMT). We find that the gene for EMT master regulator Snail (SNAI1), but not Slug (SNAI2), shows evidence of Pol II pausing before activation. Transcriptional activation of the paused SNAI1 gene is accompanied by a further increase in Pol II pausing signal, whereas activation of non-paused SNAI2 gene results in the acquisition of a typical pausing signature. The increase in pausing signal reflects increased transcription initiation without changes in Pol II pausing. Activation of the heat shock HSP70 gene involves pausing release that speeds up Pol II turnover, but does not change pausing location. We suggest that Pol II pausing is retained during transcriptional activation and can further undergo regulated release in a signal-specific manner.
    MeSH term(s) Epithelial-Mesenchymal Transition/genetics ; HSP70 Heat-Shock Proteins/genetics ; Humans ; MCF-7 Cells ; Promoter Regions, Genetic ; RNA Polymerase II/metabolism ; Snail Family Transcription Factors ; Transcription Factors/genetics ; Transcriptional Activation
    Chemical Substances HSP70 Heat-Shock Proteins ; SNAI1 protein, human ; SNAI2 protein, human ; Snail Family Transcription Factors ; Transcription Factors ; RNA Polymerase II (EC 2.7.7.-)
    Language English
    Publishing date 2015-04-30
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 186809-3
    ISSN 1362-4962 ; 1362-4954 ; 0301-5610 ; 0305-1048
    ISSN (online) 1362-4962 ; 1362-4954
    ISSN 0301-5610 ; 0305-1048
    DOI 10.1093/nar/gkv263
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Quality control methods for optimal BCR-ABL1 clinical testing in human whole blood samples.

    Stanoszek, Lauren M / Crawford, Erin L / Blomquist, Thomas M / Warns, Jessica A / Willey, Paige F S / Willey, James C

    The Journal of molecular diagnostics : JMD

    2013  Volume 15, Issue 3, Page(s) 391–400

    Abstract: Reliable breakpoint cluster region (BCR)--Abelson (ABL) 1 measurement is essential for optimal management of chronic myelogenous leukemia. There is a need to optimize quality control, sensitivity, and reliability of methods used to measure a major ... ...

    Abstract Reliable breakpoint cluster region (BCR)--Abelson (ABL) 1 measurement is essential for optimal management of chronic myelogenous leukemia. There is a need to optimize quality control, sensitivity, and reliability of methods used to measure a major molecular response and/or treatment failure. The effects of room temperature storage time, different primers, and RNA input in the reverse transcription (RT) reaction on BCR-ABL1 and β-glucuronidase (GUSB) cDNA yield were assessed in whole blood samples mixed with K562 cells. BCR-ABL1 was measured relative to GUSB to control for sample loading, and each gene was measured relative to known numbers of respective internal standard molecules to control for variation in quality and quantity of reagents, thermal cycler conditions, and presence of PCR inhibitors. Clinical sample and reference material measurements with this test were concordant with results reported by other laboratories. BCR-ABL1 per 10(3) GUSB values were significantly reduced (P = 0.004) after 48-hour storage. Gene-specific primers yielded more BCR-ABL1 cDNA than random hexamers at each RNA input. In addition, increasing RNA inhibited the RT reaction with random hexamers but not with gene-specific primers. Consequently, the yield of BCR-ABL1 was higher with gene-specific RT primers at all RNA inputs tested, increasing to as much as 158-fold. We conclude that optimal measurement of BCR-ABL1 per 10(3) GUSB in whole blood is obtained when gene-specific primers are used in RT and samples are analyzed within 24 hours after blood collection.
    MeSH term(s) Clinical Laboratory Techniques/methods ; DNA Primers/genetics ; DNA, Complementary/genetics ; Fusion Proteins, bcr-abl/blood ; Fusion Proteins, bcr-abl/genetics ; Glucuronidase/genetics ; Humans ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/blood ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics ; Quality Control ; RNA/genetics ; RNA/isolation & purification ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; Sensitivity and Specificity
    Chemical Substances BCR-ABL1 fusion protein, human ; DNA Primers ; DNA, Complementary ; RNA (63231-63-0) ; Fusion Proteins, bcr-abl (EC 2.7.10.2) ; Glucuronidase (EC 3.2.1.31)
    Language English
    Publishing date 2013-03-27
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2000060-1
    ISSN 1943-7811 ; 1525-1578
    ISSN (online) 1943-7811
    ISSN 1525-1578
    DOI 10.1016/j.jmoldx.2013.02.004
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top